By: James Peacock
With an outbreak of Cyclosporiasis currently occurring in Texas, investigators with the Texas Department of State Health Services are searching for a cause. There has been a spike in illnesses in Texas beginning in mid-June. There were only 148 cases of Cyclospora poisoning reported in Texas throughout the entire year of 2016. The current outbreak has sickened 68 people in just one month. Health officials are conducting interviews with ill individuals in order to pinpoint a common vehicle for exposure. Because person-to-person infections are unlikely with Cyclospora, the interviews have most likely focused on food and drinks. There have been outbreaks of Cyclospora linked to fresh produce in the past, including cilantro, raspberries, basil, and lettuce. In addition to outbreaks that are currently occurring even beyond the one in Texas, in this article we take a look at past outbreaks to help shed light on the nature of Cyclospora outbreaks.
In an outbreak investigation that was last updated on July 14, the Public Health Agency of Canada has announced that at least 57 people who have been sickened by Cyclospora protozoa. There are two provinces that have reported cases of illness: British Columbia with five cases and Ontario with 52 cases. The illnesses began to occur in May and continued through June. The outbreak investigation was initially announced by Canadian health officials on June 29, 2017. The investigation has not pinpointed a source, but because Cyclospora a very unlikely to survive in the water supply or on locally grown food in Canada, it is likely that the outbreak was caused by imported produce.
There is also an outbreak of Cyclosporiasis currently occurring in the United Kingdom. This outbreak was first announced by the European Centre for Disease Prevention and Control on July 17. The latest update to the outbreak was provided on July 21. There are currently 43 cases of illness connected to this outbreak. Eleven people out of the 25 for whom travel information is available traveled to Mexico prior to their illness. This marks the third year in a row that an uptick in Cyclospora poisoning has occurred in the United Kingdom as a result of travel to Mexico. Ten of the other cases of illness were from traveling elsewhere, and the last four for which travel information is known did not travel. France and Belgium have also reported cases of Cyclosporiasis in people that have traveled to Mexico.
History of Cyclospora outbreaks
There were 32 reported outbreaks of Cyclosporiasis between 2000 and 2015. About two outbreaks were reported each year, and there was an average of 21 cases of illness per outbreak. The sources for the outbreaks have been found on 14 occasions. Out of the latest four outbreaks, sources have been found for two of them. In June of 2014, 14 people were sickened in the state of Michigan. The source of this outbreak was never found. Also in June 2014, Texas reported 26 cases of Cyclospora poisoning. This outbreak was linked to cilantro from Puebla, Mexico. In July of 2014, South Carolina reported 13 cases of illness, but a source was never found. Between May and July 2015, 90 cases of illness were reported in Georgia, Wisconsin, and Texas. The source of the outbreak was eventually found to be cilantro, again from Puebla, Mexico.
With a couple of large Cyclospora outbreaks happening recently, the FDA decided to take action. In 2015, they announced that they were limiting the cilantro being imported from Puebla, Mexico. The FDA cited consecutive annual outbreaks being caused by the cilantro as a reason for the import alert. Inspections of the growing and processing areas for this cilantro revealed that there was fecal contamination in the fields, inadequate hand washing, and potential sewage exposure. This import restriction has remained in place since 2015, and was recently updated to clarify some of its language. After the FDA issued the import alert, there was a noticeable drop in Cyclospora cases. The FDA announced late last year that Cyclospora cases were actually on the decline for the first time in years. It appears as though the restriction had a positive effect. When the restrictions, travel-related outbreaks, import-related outbreaks, and past outbreaks are taken as a whole, it is not much of a stretch to imagine that investigators are looking into produce being imported from Mexico. As they progress with the investigation, though, consumers will eventually get a better idea as to what caused the outbreak, whether it was produce from Mexico or somewhere else.
Cyclospora are single celled protozoa that can be found in a variety of animals and environments. There are quite a few different types of Cyclospora, but only one species, Cyclospora cayetanensis, has been known to cause illness in humans. Immature oocysts are shed through feces. It takes around one or two weeks outside of the body in order to mature. After this maturation process, Cyclospora can become infective. Not much is known about the number of protozoa required to cause a case of illness, but upon exposure to the protozoa, symptoms will appear between 7 and 10 days afterward. There is a myriad of symptoms that can present with a Cyclospora infection including loss of appetite, weight loss, watery diarrhea, nausea, abdominal cramping, bloating, headache, fever, vomiting, and body aches. These symptoms can last up to months, although they may go away within a few days. There is a chance that the illness will return even after symptoms originally subside. According to the CDC estimates from January of 2011, there had been no deaths attributed to Cyclospora infections. However, Cyclospora infections can still be fairly serious, and can even result in hospitalization being required. Anyone can get a Cyclospora infection. However, children, the elderly, those with suppressed immune systems, and those living in tropical or subtropical areas are more likely to catch a Cyclospora infection. Cyclospora infections are much more common in the summer than in the winter. In the United States, the majority of Cyclospora infections take place between May and July.
Cyclospora Testing and Diagnosis
If you or a loved one begins to show the symptoms of a Cyclospora infection, it is a good idea to go see a doctor. Often, the doctor will recommend rest and hydration, but they will also likely run some tests in an effort to narrow down the cause of the infection. Cyclospora is not necessarily tested for on every occasion, so if you believe that you have a Cyclospora infection and are presenting the symptoms listed above, it is a good idea to suggest that your doctor run a Cyclospora test. This test involves a stool sample, and attempts to isolate Cyclospora oocysts. There are quite a few steps that are involved in sampling and testing for Cyclospora. For more information about the testing process, click here. If you test positive for a Cyclospora infection, the doctor will likely prescribe a round of antibiotics. The antibiotic Trimethoprim/sulfamethoxazole, usually sold under the names Bactrim, Septra, or Cotrim, is typically used to treat cases of Cyclosporiasis.